Decoding Long Term Fuel Trim Without the Headache
Alex and Emma break down long term fuel trim, explaining what positive and negative percentages actually mean for your engine. Learn how to spot vacuum leaks, fuel delivery problems, and why clearing codes never fixes the real issue.
In this episode
Positive fuel trim means the engine computer is adding extra fuel to fix a lean condition.
Negative fuel trim means the computer is removing fuel because the mixture is running rich.
Checking trim at idle versus under acceleration helps pinpoint vacuum leaks versus fuel delivery faults.
Short term and long term fuel trim work together to show…
The skinny
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